Pipe failures in US commercial nuclear power plants

Recent NRC mandates require utilities to perform probabilistic risk assessments as part of their individual plant examinations (IPEs). To date, a significant number of IPEs have identified small-break loss-of-coolant accidents (LOCAs) as a major contributor to nuclear power plant risk. Most existing databases that address pipe failure rates have been based on judgmental estimates from industry experts. EPRI has developed a methodology and database that uses actual experiences to support failure rate calculations on a plant-or system-specific basis. This document discusses this methodology